public class Example4_19 {
    public static void main(String args[]) {
        Student2 zhang = new Student2();
        Student2 geng=new Student2();
        zhang.setAge(23);
        System.out.println("张的年龄:"+zhang.getAge());
        geng.setAge(25);
        System.out.println("geng的年龄:"+geng.getAge());
    }
}
